Description

This is a replica of this issue: Automattic/wp-calypso#56077

Step-by-step reproduction instructions

Steps to Reproduce

1. Start by opening a page to edit
2. Click the blue plus sign to open the blocks & pattern search sidebar
3. Go to Patterns → Headers (in the Patterns drop down)
4. Start scrolling. The second pattern, "Large header with text and a button" does not load correctly and breaks the entire pattern selection box.

I tested this on Chrome and did not see the same error/issue.

In Safari, I also got an error that "This webpage is using significant memory. Closing it may improve the responsiveness of your Mac."

I'm currently running Safari Version 14.1.2 (16611.3.10.1.6) on macOS Big Sur, version 11.5.2. 16" 2019 MacBook Pro.

Video of the error:

Screenshots, screen recording, code snippet

No response

Environment info

Operating System

macOS

OS Version

11.5.2

Browser

Safari

Browser Version(s)

14.1.2

Is this specific to applied theme? If so, what is the theme name?

I tested using Blank Canvas and also Bradford. Issue happened on both themes.

Console and/or error logs

No response

Available Workarounds

You can use a different web browser - I was able to select a header pattern in Chrome.

Reproducibility

No response

Other information

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes